Electric switch



June 17, 1924; 1,498,090

B. E. GETCHELL l ELECTRIC SWITCH II FiledAprll 26 1920 2 Sheets-Sheet 1June 17, 1924. 1,498,090 v B. E. GETCHELL ELECTRIC SWITCH Filed April 261920 2 SheetsfSheat -2 1b W l a m u I Qi 1 b ub `1 T A 3 Q g3 f n l l bgR* A u El( O o; f N N n 2g Inventor: .ece

' r Atty Patented une 17, 1924.

' UNITED STATES PATENT OFFICE.

BENJAMIN E. GETCHELL, F PLAIN'VILLE, CONNECTICUT, ASSIGNOR TO THE TRUM-BULL ELECTRIC MFG. COMPANY, OF PLAINVILLE, CONNECTICUT, A CORPORATION OFCONNECTICUT.

ELECTRIC SWITCH.

` Application led April 26, 1920. Serial No. 376,804.

cation.

My invention relates to a switch for starting and protecting a motor orthe like.

My main object is to provide a simple,

rugged, and reliable construction which may be operated by a normalthrow of a handle to either close or open the circuit and which willopen with a quick break action either by hand or automatically in caseof under voltage or overload condition even should the operator attemptto hold the handle.

In its referred form, the switch embodies ordinary well known knifeblade type of switch contacts adapted to be operated by hand. A speciallink and spring connection between the handle and the switch bladesenables the operator to close the circuit by a single throw of thehandle. The switch is adapted to be opened by hand by the usual singlethrow of the handle, whereupon the link motion and spring will break thecircuit with a snap action independently of the control of the operator.A no-voltage or under-voltage magnet is adapted to release the quickbreak mechanism upon occurrence of over-load or low voltage, even thoughthe handle be held in the on position. This holds. true either at thetime of starting or at any subsequent time while the motor is inoperation.l The circuit throu h the no-voltage magnet can be controllefrom a distance as well as through the conditions in the switch itself.An overload switch is also provided which is adapted to release theswitch mechanism in case of excessive overload. This also is independentofthe operator.

Fi 1 is a front view of a switch einbodying the improvements of myinvention, the cover being omitted and parts shown in the closed circuitposition.

Fig. 2 is a side view and partial vertical section of the same.

Fig. 3 is a similar View showing the switch in the open circuit positionand omitting theoverload switch.

Fig. 4 is a diagrammatic View showing the circuits through the switch.

In its preferred form, all the parts with the exception of the handleare enclosed in a box or receptacle 6. The circuit terminals are carriedby an insulating base 7.

Each of the three knife blades 8,18', and

8 is hinged to a post such as 9, 9', 9 and adapted to engage a stationarcontact such as 10, 10', 10". The bla es are carried by an insulatingcross bar 11. An operating shaft 12 has its ends 13 pivoted in the box,and is connected to the cross bar 11 by one or more links 14.

.The operating handle 15 has its hub 16 pivotally mounted in one wall ofthe box.

The handle crank 17 has one end connecti I ed to the hub 16 and theother pivoted in a bracket 18. This crank 17 is connected to thecrank-shaft 12 by means of a folding or hinged rod made up of the twoarts 19 and 2O hinged together at 21. A atch 22 is pivoted on thecrank-shaft 12 :and provided with a shoulder 23 which normally engagesthe tip 24 on the up er end of the part 19. spring 25 has its ower endconnect'ed to the box, and its upper end connected to 'the rod 20between the shaft 12 and the hinge 21. When the parts are in a positionshown in Fig. 2, this spring exerts a downward tension on the bar 20,the longitudinal component of which thrusts against the hinge 21 andtends `to push the bar 19 downwardly. As the crank 17 in this positionis in rear of the center line connecting the bearing in the bracket 18and the crankshaft 12, Ithe action of the spring is to forcibly hold theswitch in the closed circuit position. The latch 22 is notched at 26 soas to allow a limited swinging motion of the latch with relation to thestud 27 at theupp'er end of the bar 20.

A releasing member` 28 hinged at 29 lis connected to or forms a part ofthe armature of the magnet having the coil 30. The magnet when energizedholds up the releasing member 28 against the pressure of the spring 31.In case the current fails in the magnet, the armature is released andthe spring 31 forces the member 28 downward into engagement with thetai-l of the latch 22. This releases the shoulder 23 from l cation, anddis osition of the weight of the parts is suc as to cause the shoulder23 to automatically re-engage the tip 24 so that the parts are invposition to be again set into closed circuit position without furtherattention or operation. A catch 28 may be provided for tripping thelatch 22 when the switch is to be manually operated.

By providing one or more normally closed circuit switches such as 32 inthe circuit of the magnet coil 30, I may control the switch from any-oneor more remote places.

I also provide an overload switch having coils 33 andl 33 with movablecores 34C and 34 which are adapted to engage and lift the v armature 35and open the switch 36 in case of an overload. The main line conductors'are connected at 37, 37 and 37 and the local circuit or load conductorsare connect ed to the terminals 38, 38 and 38. The solenoid coil 33 isconnected between the terminals 9 and 38 at one side and the coil 33 isconnected between the terminals 9 and 38" on the other side. The novoltage or low voltage release coil 30 is connected in series with theswitch 36 between the terminals 38 and 38. Iny case of an overload, thesolenoids 33 and 33 lift the armature 35 and open the switch 36 throughthe shunt circuit which includes the release magnet coil 30, which beingthus deenergized, releases the armature and member 28 so as to trip thelatch22 and allow the spring 25 to break the circuit.

It will be noted that the closing movement of the switch is the usualtype of single throw movement. The overload coils 33 and 33 will be sodesigned that the time limit of their action will take care of thestarting current. Under voltage or excessive overload will vcause theswitch to 4open instantly even though the operator may attempt to holdit by the handle. This holds true either at the time of starting themotor or at any other time while the motor is in op eration. On theother hand, the manual openin of the switch is effected by means of theandle. When once the switch starts to open, the circuit is interruptedwith a quick break which cannot be controlled by the operator. No pushbutton release is necessary unless it is desired to be able to open theswitch from some remote point, in which case, the circuit of theundervoltage release magnet may be extended to a switch or push button 32 inany desired location.

Only a single main spring is required in this construction and serves toprovide a quick'break both on the hand operation and on the automaticoperation and also serves to automatically relatch themechanism. Bypivoting the switch yoke above the switch pivot and close to the back ofthe box and locating the handle pivot below the switch should beunderstood that with an enclosed type of switch of this character asafety latch maybe used if desired. Reference may #1,310,163 for a typesuitable to be used in be had to the Knudsen Patent this connection. Byusing a magnet type of under voltage release coil, I am able to useamuch more ruggedl winding than is possible with a solenoid type, and theaction is more positive and powerful. All the parts are so constructedthat they may be made economically, and they are so arranged that theymay be readily removed for repairs and replacements.

By this construction I eliminate the necessity for the use of fuses, andthus practically eliminate motor burnouts which are largely due to thebreaking of one fuse and leaving the motor operating single phase. Withthis switch an overload on eitherphase will open the entire motorcircuit.

I claim:

1. In an electric switch, `the combination of a movable contact, aswinging handle, quick break mechanism connecting said handle and saidcontact and including a spring and latch for normally holding said partsin their closed circuit position, means for releasing said latch whenthe handle is operated by hand and means for releasing said latch incaseof an overload on the circuit, even when the handle is maintained icontact closing position.

2. In an electric switch, the combination of a movable contact, aswinging handle, quick break mechanism connecting said handle and saidcontact including a spring and latch for normally holding said rparts intheir closed circuit position, means for releasing said latch when thehandle is operated by hand, means for releasing said latch in case of anoverload on the circuit, and means for releasing said latch in case offailure of voltage in the circuit of said switch, even when the handleis maintained in contact closing position.

3. In a switch, a switch casing, a switch blade, a pivoted operatingshaft, a connection between said blade and shaft, a hinged memberpivoted at one end in said casing' and at the other end to saidoperating shaft, a spring and a latch cooperating with said hingedmember, means for moving said latch upon failure of voltage in thecircuit whereby the switch will be opened by the spring with a snapaction.

4. In a switch, a switch casing, a switch blade, a pivoted operatingshaft, a connection between said blade and shaft, a hinged memberpivoted at one end in said casing soz and at the other end to saidoperating shaft, a spring and a latch cooperating with said hingedmember, means Jfor moving said latch in case of an overload on thecircuit whereby the switch will be opened by the spring with a snapaction.

5. In a switch, a switch blade, an operating crank, a normall rigidhinged member connecting said bla e and crank Whereb when the crank ismanipulated the switch will be opened or closed, means for breaking therigidity of said hinge member upon failure of current to the switch,means for breaking the rigidity of said hinge member when the openingmovement of the switch is initiated by the crank, and a spring foropening the switch with a snap action as soon as the rigidity ofthehinge member is broken.

6. In an electric switch, a movable switch member, a hand o eratedcrank, a swin ing member connecte to said switch mem er, a hinged memberconnecting said hand oper? ated crank to said swinging member, a latchpivotally mounted on said swinging member for holding the parts of saidhinged member in a substantially straight line relation, means forengaging said latch to release it when said hand operated crank is movedby hand, and electro magnetically controlled means for releasing saidlatch, even when said hand operated crank is manually prevented frommoving.

7. In an electric switch of the character described, a swinging member,a latch pivotally mounted thereon and having a` limited y motion withrelation thereto, an operating crank, a member connecting said operatingcrank with said swinging member consisting of two parts hinged to eachother, one part normally engaging said latch, means for releasing saidlatch from said part when said crank is operated by hand, and means forreleasing said latch upon a change in electrical condition in theapparatus.

8. In an electric switch, a movable mem ber, a latch pivotally carriedthereby, a hand operable crank, a bar connected to Said crank andnormally engaging said latch, a second bar hinged to said vfirstmentioned bar and connected to said movable member, a trip member forengaging said latch when said crank is operated by hand, and anelectrically controlled member for engaging said latch.

9. In an electric switch, a movable member, a latch relativelystationary trip for engaging one end of said latch, an electricallycontrolled member for engaging the opposite end of said latch, a handoperable crank, a bar 'connected to said crank and normally held by saidlatch, and a second bar hinged to said first bar and to said movablemember.

10. In an electric switch, a movable member, a latch pivotally carriedthereby, a relatively stationary trip for engaging one end of saidlatch, an electrically controlled member forenga ing the opposite end ofsaid latch, a han operable crank, a bar connected to said crank andnormally held by said latch, a second bar hinged to said first bar andto said movable member, and a .spring connected to said second bar formovin said movable member when said latch 1s re eased and returning saidfirst bar to its normal engagement with said latch.

11. In an electric switch, a movable member, a latch pivoted thereto, ahand operable crank, a bar connected to said crank and normally engaginga shoulder of said latch, a second bar connected to said first bar andto said movable member, a spring connected to said second bar, means forengaging one end of said latch to release it when said crankis operatedby hand, and electrically controlled means for engaging the op osite endof said latch to release it from sai first part.

BENJAMIN E. GETCHELL.

ivotally carried thereby, n

